My questions relate to how to best repurpose an older 1TB G-RAID mini (Firewire only).

Rather than opt for the speed of a RAID0 (susceptible to failure if one drive goes) or the mirroring of a RAID1 (protected, but reduces available storage to 500GB), I'd like to access both internal drives as two individual 500GB drives, maximizing available storage at 1TB yet where one drive's failure has no impact on the second drive.

How can I do this using OS X's Disk Utility ?

1) Partition tab >> set Partition Layout to two (2) partitions, each 500GB in size ?

or

2) RAID tab >> set RAID Type to Concatenated Disk Set (JBOD) ?

I prefer to access each internal drive independently, so portions of a large file aren't spanned across both disks, but reside as complete files on a respective HDD.

I'm uncertain if partitioning as two 500GB partitions is equivalent to *physically* accessing each internal drive as if it were a stand-alone drive (say, like two 500GB G-Drive minis), which is what I hope to achieve.

Thanks for your post. As it turns out, the G-RAID Mini cannot be setup as a JBOD, only as a RAID 0 or a RAID 1. Since it is a hardware RAID, Disk Utility cannot access the drives individually, and the G-RAID Mini only appears as a single drive to the OS. Please let me know if you have any questions.